The present invention relates generally to axial flux machines.
Axial flux machines, sometimes referred to as disk, axial-gap, or pancake motors, are presently used in appliances that have low to modest power requirements such as video cassette recorders and blenders, for example.
There is a particular need for a simple fabrication process for providing an axial flux motor having increased power density and efficiency.
Briefly, in accordance with one embodiment of the present invention, an axial flux machine comprises: a rotatable shaft; a rotor disk coupled to the rotatable shaft; a permanent magnet supported by the rotor disk; a soft magnetic composite stator extension positioned in parallel with the rotor disk and having slots; soft magnetic composite pole pieces attached to the stator extension and facing the permanent magnet, each comprising a protrusion situated within a respective one of the slots, each protrusion shaped so as to facilitate orientation of the respective pole piece with respect to the stator extension; and electrical coils, each wrapped around a respective one of the pole pieces. In accordance with another embodiment of the present invention, an axial flux machine stator comprises: a soft magnetic composite stator extension having slots; soft magnetic composite pole pieces attached to the stator extension, each comprising a protrusion situated within a respective one of the slots, each protrusion shaped so as to facilitate orientation of the respective pole piece with respect to the stator extension; and electrical coils, each wrapped around a respective one of the pole pieces.
In accordance with another embodiment of the present invention, An axial flux machine comprises: a rotatable shaft; a rotor disk coupled to the rotatable shaft; a permanent magnet supported by the rotor disk; a soft magnetic composite stator extension positioned in parallel with the rotor disk; soft magnetic composite pole pieces attached to the stator extension and facing the permanent magnet, each comprising a base portion and a trapezoidal shield portion, the trapezoidal shield portion having a plurality of heights with a first height in a first region being longer than a second height in a second region, the second region being closer to a pole-to-pole gap than the first region; and electrical coils, each respective electrical coil wrapped around a respective base portion of a respective pole piece with a respective trapezoidal shield portion extending over at least part of the respective electrical coil.
In accordance with another embodiment of the present invention, an axial flux machine stator comprises a soft magnetic composite stator extension; soft magnetic composite pole pieces attached to the stator extension, each comprising a base portion and a trapezoidal shield portion, the trapezoidal shield portion having a plurality of heights with a first height in a first region being longer than a second height in a second region, the second region being closer to a pole-to-pole gap than the first region; and electrical coils, each respective electrical coil wrapped around a respective base portion of a respective pole piece with a respective trapezoidal shield portion extending parallel to the stator extension over at least part of the respective electrical coil.
In accordance with another embodiment of the present invention, an axial flux machine stator pole piece comprises: a soft magnetic composite base portion; a soft magnetic composite trapezoidal shield portion coupled to a first end of the base portion, the trapezoidal shield portion comprising a plurality of heights with a first height in a first region being longer than a second height in a second region, the second region being further from the base portion than the first region; and a protrusion coupled to a second end of the base portion and shaped so as to facilitate orientation of the respective pole piece.
In accordance with another embodiment of the present invention, a method of fabricating an axial flux machine stator comprises attaching soft magnetic composite pole pieces to a soft magnetic composite stator extension by situating protrusions of the pole pieces within respective slots of the stator extension, each protrusion shaped so as to facilitate orientation of the respective pole piece with respect to the stator extension.